1887
Research Open Access
Like 0

Abstract

Background

Contact tracing was one of the central non-pharmaceutical interventions implemented worldwide to control the spread of SARS-CoV-2, but its effectiveness depends on its ability to detect contacts.

Aim

Evaluate the proportion of secondary infections captured by the contact tracing system in Geneva.

Methods

We analysed 166,892 concomitant infections occurring at the same given address from June 2020 until February 2022 using an extensive operational database of SARS-CoV-2 tests in Geneva. We used permutation to compare the total number of secondary infections occurring at the same address with that reported through manual contact tracing.

Results

Contact tracing captured on average 41% of secondary infections, varying from 23% during epidemic peaks to 60% during low epidemic activity. People living in wealthy neighbourhoods were less likely to report contacts (odds ratio (OR): 1.6). People living in apartment buildings were also less likely to report contacts than those living in a house (OR: 1.1–3.1) depending on the SARS-CoV-2 variant, the building size and the presence of shops. This under-reporting of contacts in apartment buildings decreased during periods of mandatory wearing of face masks and restrictions on private gatherings.

Conclusion

Contact tracing alone did not detect sufficient secondary infections to reduce the spread of SARS-CoV-2. Campaigns targeting specific populations, such as those in wealthy areas or apartment buildings, could enhance coverage. Additionally, measures like wearing face masks, improving ventilation and implementing restrictions on gatherings should also be considered to reduce infections resulting from interactions that may not be perceived as high risk.

Loading

Article metrics loading...

/content/10.2807/1560-7917.ES.2024.29.3.2300228
2024-01-18
2024-04-27
http://instance.metastore.ingenta.com/content/10.2807/1560-7917.ES.2024.29.3.2300228
Loading
Loading full text...

Full text loading...

/deliver/fulltext/eurosurveillance/29/3/eurosurv-29-3-5.html?itemId=/content/10.2807/1560-7917.ES.2024.29.3.2300228&mimeType=html&fmt=ahah

References

  1. Flaxman S, Mishra S, Gandy A, Unwin HJT, Mellan TA, Coupland H, et al. Estimating the effects of non-pharmaceutical interventions on COVID-19 in Europe. Nature. 2020;584(7820):257-61.  https://doi.org/10.1038/s41586-020-2405-7  PMID: 32512579 
  2. Liu Y, Morgenstern C, Kelly J, Lowe R, Jit M, CMMID COVID-19 Working Group. The impact of non-pharmaceutical interventions on SARS-CoV-2 transmission across 130 countries and territories. BMC Med. 2021;19(1):40.  https://doi.org/10.1186/s12916-020-01872-8  PMID: 33541353 
  3. Suryanarayanan P, Tsou C-H, Poddar A, Mahajan D, Dandala B, Madan P, et al. AI-assisted tracking of worldwide non-pharmaceutical interventions for COVID-19. Sci Data. 2021;8(1):94.  https://doi.org/10.1038/s41597-021-00878-y  PMID: 33767205 
  4. Hossain AD, Jarolimova J, Elnaiem A, Huang CX, Richterman A, Ivers LC. Effectiveness of contact tracing in the control of infectious diseases: a systematic review. Lancet Public Health. 2022;7(3):e259-73.  https://doi.org/10.1016/S2468-2667(22)00001-9  PMID: 35180434 
  5. Kojaku S, Hébert-Dufresne L, Mones E, Lehmann S, Ahn YY. The effectiveness of backward contact tracing in networks. Nat Phys. 2021;17(5):652-8.  https://doi.org/10.1038/s41567-021-01187-2  PMID: 34367312 
  6. Raymenants J, Geenen C, Thibaut J, Nelissen K, Gorissen S, Andre E. Empirical evidence on the efficiency of backward contact tracing in COVID-19. Nat Commun. 2022;13(1):4750.  https://doi.org/10.1038/s41467-022-32531-6  PMID: 35963872 
  7. Kretzschmar ME, Rozhnova G, Bootsma MCJ, van Boven M, van de Wijgert JHHM, Bonten MJM. Impact of delays on effectiveness of contact tracing strategies for COVID-19: a modelling study. Lancet Public Health. 2020;5(8):e452-9.  https://doi.org/10.1016/S2468-2667(20)30157-2  PMID: 32682487 
  8. Pozo-Martin F, Beltran Sanchez MA, Müller SA, Diaconu V, Weil K, El Bcheraoui C. Comparative effectiveness of contact tracing interventions in the context of the COVID-19 pandemic: a systematic review. Eur J Epidemiol. 2023;38(3):243-66.  https://doi.org/10.1007/s10654-023-00963-z  PMID: 36795349 
  9. Ferretti L, Wymant C, Kendall M, Zhao L, Nurtay A, Abeler-Dörner L, et al. Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing. Science. 2020;368(6491):368.  https://doi.org/10.1126/science.abb6936  PMID: 32234805 
  10. European Commission, Directorate-General for Communications Networks Content and Technology. Digital contact tracing study: study on lessons learned, best practices and epidemiological impact of the common European approach on digital contact tracing to combat and exit the COVID 19 pandemic. Luxembourg: Publications Office of the European Union; 2022. Available from: https://op.europa.eu/en/publication-detail/-/publication/69f8bd22-7065-11ed-9887-01aa75ed71a1/language-en
  11. Wymant C, Ferretti L, Tsallis D, Charalambides M, Abeler-Dörner L, Bonsall D, et al. The epidemiological impact of the NHS COVID-19 app. Nature. 2021;594(7863):408-12.  https://doi.org/10.1038/s41586-021-03606-z  PMID: 33979832 
  12. Vogt F, Haire B, Selvey L, Katelaris AL, Kaldor J. Effectiveness evaluation of digital contact tracing for COVID-19 in New South Wales, Australia. Lancet Public Health. 2022;7(3):e250-8.  https://doi.org/10.1016/S2468-2667(22)00010-X  PMID: 35131045 
  13. Wang X, Du Z, James E, Fox SJ, Lachmann M, Meyers LA, et al. The effectiveness of COVID-19 testing and contact tracing in a US city. Proc Natl Acad Sci USA. 2022;119(34):e2200652119.  https://doi.org/10.1073/pnas.2200652119  PMID: 35969766 
  14. Hellewell J, Abbott S, Gimma A, Bosse NI, Jarvis CI, Russell TW, et al. Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts. Lancet Glob Health. 2020;8(4):e488-96.  https://doi.org/10.1016/S2214-109X(20)30074-7  PMID: 32119825 
  15. Greenhalgh T, Jimenez JL, Prather KA, Tufekci Z, Fisman D, Schooley R. Ten scientific reasons in support of airborne transmission of SARS-CoV-2. Lancet. 2021;397(10285):1603-5.  https://doi.org/10.1016/S0140-6736(21)00869-2  PMID: 33865497 
  16. Zhang R, Li Y, Zhang AL, Wang Y, Molina MJ. Identifying airborne transmission as the dominant route for the spread of COVID-19. Proc Natl Acad Sci USA. 2020;117(26):14857-63.  https://doi.org/10.1073/pnas.2009637117  PMID: 32527856 
  17. Wong S-C, Au AK-W, Chen H, Yuen LL, Li X, Lung DC, et al. Transmission of Omicron (B.1.1.529) - SARS-CoV-2 Variant of Concern in a designated quarantine hotel for travelers: a challenge of elimination strategy of COVID-19. Lancet Reg Health West Pac. 2022;18:100360.  https://doi.org/10.1016/j.lanwpc.2021.100360  PMID: 34961854 
  18. Stern RA, Charness ME, Gupta K, Koutrakis P, Linsenmeyer K, Madjarov R, et al. Concordance of SARS-CoV-2 RNA in aerosols from a nurses station and in nurses and patients during a hospital ward outbreak. JAMA Netw Open. 2022;5(6):e2216176.  https://doi.org/10.1001/jamanetworkopen.2022.16176  PMID: 35675074 
  19. Lu J, Gu J, Li K, Xu C, Su W, Lai Z, et al. COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020. Emerg Infect Dis. 2020;26(7):1628-31.  https://doi.org/10.3201/eid2607.200764  PMID: 32240078 
  20. Wei H-Y, Chang C-P, Liu M-T, Mu J-J, Lin YJ, Dai Y-T, et al. Probable aerosol transmission of SARS-CoV-2 through floors and walls of quarantine hotel, Taiwan, 2021. Emerg Infect Dis. 2022;28(12):2374-82.  https://doi.org/10.3201/eid2812.220666  PMID: 36322955 
  21. Genecand C, Mongin D, Koegler F, Lebowitz D, Regard S, Falcone JL, et al. Cohort profile: actionable register of Geneva outpatients and inpatients with SARS-CoV-2 (ARGOS). BMJ Open. 2021;11(11):e048946.  https://doi.org/10.1136/bmjopen-2021-048946  PMID: 34848509 
  22. Mongin D, Cullati S, Kelly-Irving M, Rosselet M, Regard S, Courvoisier DS, Covid-SMC Study Group. Neighbourhood socio-economic vulnerability and access to COVID-19 healthcare during the first two waves of the pandemic in Geneva, Switzerland: A gender perspective. EClinicalMedicine. 2022;46:101352.  https://doi.org/10.1016/j.eclinm.2022.101352  PMID: 35360147 
  23. Mongin D, Bürgisser N, Laurie G, Schimmel G, Vu DL, Cullati S, et al. Effect of SARS-CoV-2 prior infection and mRNA vaccination on contagiousness and susceptibility to infection. Nat Commun. 2023;14(1):5452.  https://doi.org/10.1038/s41467-023-41109-9  PMID: 37673865 
  24. Hodcroft EB. CoVariants: SARS-CoV-2 Mutations and Variants of Interest. [Accessed: 22 Aug 2023]. Available from: https://covariants.org/
  25. Elbe S, Buckland-Merrett G. Data, disease and diplomacy: GISAID’s innovative contribution to global health. Glob Chall. 2017;1(1):33-46.  https://doi.org/10.1002/gch2.1018  PMID: 31565258 
  26. De Cáceres M, Legendre P. Associations between species and groups of sites: indices and statistical inference. Ecology. 2009;90(12):3566-74.  https://doi.org/10.1890/08-1823.1  PMID: 20120823 
  27. R Core Team. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing; 2020. Available from: http://www.Rproject.org/
  28. Wu Y, Kang L, Guo Z, Liu J, Liu M, Liang W. Incubation Period of COVID-19 Caused by Unique SARS-CoV-2 Strains: A Systematic Review and Meta-analysis. JAMA Netw Open. 2022;5(8):e2228008.  https://doi.org/10.1001/jamanetworkopen.2022.28008  PMID: 35994285 
  29. Kucharski AJ, Klepac P, Conlan AJK, Kissler SM, Tang ML, Fry H, et al. Effectiveness of isolation, testing, contact tracing, and physical distancing on reducing transmission of SARS-CoV-2 in different settings: a mathematical modelling study. Lancet Infect Dis. 2020;20(10):1151-60.  https://doi.org/10.1016/S1473-3099(20)30457-6  PMID: 32559451 
  30. Davis EL, Lucas TCD, Borlase A, Pollington TM, Abbott S, Ayabina D, et al. Contact tracing is an imperfect tool for controlling COVID-19 transmission and relies on population adherence. Nat Commun. 2021;12(1):5412.  https://doi.org/10.1038/s41467-021-25531-5  PMID: 34518525 
  31. Liu Y, Rocklöv J. The effective reproductive number of the Omicron variant of SARS-CoV-2 is several times relative to Delta. J Travel Med. 2022;29(3):taac037.  https://doi.org/10.1093/jtm/taac037  PMID: 35262737 
  32. Liu Y, Rocklöv J. The reproductive number of the Delta variant of SARS-CoV-2 is far higher compared to the ancestral SARS-CoV-2 virus. J Travel Med. 2021;28(7):taab124.  https://doi.org/10.1093/jtm/taab124  PMID: 34369565 
  33. Clark E, Chiao EY, Amirian ES. Why Contact Tracing Efforts Have Failed to Curb Coronavirus Disease 2019 (COVID-19) Transmission in Much of the United States. Clin Infect Dis. 2021;72(9):e415-9.  https://doi.org/10.1093/cid/ciaa1155  PMID: 32761123 
  34. Lash RR, Donovan CV, Fleischauer AT, Moore ZS, Harris G, Hayes S, et al. COVID-19 Contact Tracing in Two Counties - North Carolina, June-July 2020. MMWR Morb Mortal Wkly Rep. 2020;69(38):1360-3.  https://doi.org/10.15585/mmwr.mm6938e3  PMID: 32970654 
  35. Swiss Federal Office of Public Health (OFSP). FAQ : Coronavirus et règles de conduite. [Coronavirus and rules of conduct]. Bern: Swiss Federal Office of Public Health. [Accessed: 11 Dec 2023]. French. Available from: https://www.newsd.admin.ch/newsd/message/attachments/61144.pdf
  36. Piff PK, Stancato DM, Côté S, Mendoza-Denton R, Keltner D. Higher social class predicts increased unethical behavior. Proc Natl Acad Sci USA. 2012;109(11):4086-91.  https://doi.org/10.1073/pnas.1118373109  PMID: 22371585 
  37. Seuntjens TG, Zeelenberg M, van de Ven N, Breugelmans SM. Greedy bastards: Testing the relationship between wanting more and unethical behavior. Pers Individ Dif. 2019;138:147-56.  https://doi.org/10.1016/j.paid.2018.09.027 
  38. Wright L, Steptoe A, Mak HW, Fancourt D. Do people reduce compliance with COVID-19 guidelines following vaccination? A longitudinal analysis of matched UK adults. J Epidemiol Community Health. 2022;76(2):109-15.  https://doi.org/10.1136/jech-2021-217179  PMID: 34244309 
/content/10.2807/1560-7917.ES.2024.29.3.2300228
Loading

Data & Media loading...

Supplementary data

Submit comment
Close
Comment moderation successfully completed
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error